This invention relates to an improved insole which is used for conservative treatment to correct diseases of the lower limbs such as, for example, bandy legs, knock knees, fat feet, gonarthritis deformans, metatarsalgia, hallux valgus, and others. The invention is also used to supplement a person's stature for reasons of beauty and is further used for the forced inclining of the sole during athletic activities.
Heretofore, insoles that were rigid have been used for these purposes. Accordingly, there have been used in making them hard or relatively hard materials such as metals, for example, aluminum, hard plastics, leathers, cork and others.
The insoles which have for their main body hard materials as mentioned above, however, not only are inclined to be made thick so as to be strong and maintain their form, but also they must be molded so as to lap the sole form-fittingly by being deeply curved at their brim, for example, as in FIG. 1, with the object of improving poor adhesion to the sole. As result, insoles of this type are bulky on the whole, and accordingly it is difficult or impossible to use them by inserting them into socks because of their poor fit therein, as well as doing damage thereto. They are also hard to be used even as spacers for slippers or sandals (especially, of a slip-on type). They are usually used by being inserted into shoes, otherwise held on the soles with the aid of special holder made of leathers or canvas. When using such holders, however, various problems occur so that the footwear becomes hard to put on, or the holding of it is troublesome, the feedling is not good in the state of being loaded, or they cause sweating, when stained they are not washable, and so on. Further, conventional holders on the market are awkward in use, do not move well with the sole of the foot, and are accompanied by a feeling of physical disorder, especially at the time of walking in the standing position, so that it takes a considerable number of days until the user accommodates himself to the loading of them. What is more, these holders have still a hygenic problem to be solved, namely the occurrence of an offensive smell of sweat and soil resulting from the contact with the skin, particularly in the case of an insole made of leather or cork.
Under these circumstances, however, in the case of the conservative treatment or correction of diseases of lower limbs, unlike the case of the temporal use for beauty or doing athletics, for example, skiing, it is required to load the insole habitually over a considerable period of time. Since the insole heretofore in use had these various defects, many patients would withdraw the loading of them arbitrarily in the middle of the treatment. (According to certain data, the patients of this sort amounted to more than 2% of the whole: "Clinical Orthopedic Surgery", Vol XVI, No. 7, pp. 65-672, July 1981.) Some of them tell of the inefficaciousness of this treatment, others complain of physical or mental pains.